BELT-SERPENTINE 2631862 - Caterpillar

Preparing The Engine For Use
The following adjustments need only be made when starting an engine for the first time, after reconditioning the carburetor or regulator, or when changing to a different grade of fuel. Pre-starting Adjustments on Engines Equipped with Impco Carburetors: The power mixture adjustment should be set halfway between "R" (rich) and "L" (lean). No further adjustments should be made to this adjustment because turning it toward "R" tends to increase fuel consumption, and turning it toward "L" tends to reduce power. Fuel mixture adjustments should be made by changing the regulator gas pressure out of the line pressure regulator slightly. Adjust gas pressure to carburetor to compensate for higher or lower heating value of gas. Higher heating values require a reduction in pressure, while lower values would require increased pressure. See your Caterpillar dealer for necessary adjustments.
POWER MIXTURE ADJUSTMENT (Impco)Pre-starting Adjustments On Engines Equipped with Ensign Carburetor Regulator and Carburetor:1. When natural gas is used set the starting adjustment screw (2) on the carburetor four turns open. (When propane gas is used open set screw (2) one and one-quarter turns.)2. When natural gas is used set the main adjusting screw (3) on the carburetor seven turns open. (When propane gas is used open screw (3) four turns.)
CARBURETOR AND REGULATOR ADJUSTMENTS (Ensign)
1-Idle adjustment screw. 2-Starting gas adjustment screw. 3-Main gas adjustment screw.3. When natural gas is used set the idle adjustment screw (1) on the regulator one and one-fourth turns open. (When propane gas is used open screw (1) one full turn.)4. Pull the choke control out to the full choke position.Other adjustments after initial starting will be required. See the topic, CARBURETOR ADJUSTMENT.Starting The Natural Gas Engine
1. Push in the magnetic reset switch button (1) and the oil pressure gauge reset button (2).2. On earlier engines, turn the magneto switch to the "ON" position.
RESET BUTTONS
1-Magnetic switch reset button. 2-Oil pressure gauge reset button.
ENGINE CONTROLS AND GAUGE PANEL (Earlier Engines)
3-Governor control lever. 4-Oil pressure gauge. 5-Choke control. 6-Temperature gauge.3. Turn on the gas supply.4. Pull the choke control out to the full choke position for engines equipped with Ensign carburetors. Engines equipped with Impco carburetors do not have a choke.5. Move governor control lever (3) at least halfway toward the open position. The choking device on engines equipped with Ensign carburetors allows enough air and gas to enter engine on starting position to run well past idling speed with choke fully closed. If the engine is equipped with a Woodward governor the approximate half engine speed governor control position is obtained by turning the synchronizer knob (8) clockwise or in the fast direction until the indicator (9) registers "8" on the dial then turn the load limit knob (10) until the pointer on the knob is between "5" and "7" on the dial.6. Crank the engine until it starts. For the various methods of cranking the engine see the topic, STARTING THE DIESEL ENGINE in the Operation and Maintenance Instructions for the D398